I guess what was always known was that the first Kyoto commitment period would end in 2012. Therefore, plans that would be part of the second period would have to kick in right away; we couldn't wait until 2015. When the bill was presented last year, it was known that the first Kyoto period would be over in 2012. I'm still a little puzzled by this three-year gap. Why wouldn't one want the government to produce a plan in 2012 that seamlessly moves on to whatever the next agreement will be called?
On December 11th, 2007. See this statement in context.